Treatment of Experimental Choroidal Neovascularisation by Pegaptanib, VEGF TrapR1 and VEGF TrapR2

Abstract

Purpose:: Vascular endothelial growth factor (VEGF) plays an important role in choroidal neovascularisation (CNV) associated with age-related macular degeneration. We have compared the suppressive effects of pegaptanib (a selective antagonist of the VEGF₁₆₅ isoform) with VEGF Trap_R1 or VEGF Trap_R2 (both being non-selective VEGF antagonists) on experimental CNV formation in mice.

Methods:: Mice with laser-induced CNV received intravitreous injection of 2 µl pegaptanib (25 µg/µl), 1 µl VEGF Trap_R1 (1 µg/µl), 1µl VEGF Trap_R2 (1 µg/µl) or vehicle either 1 day (inhibition study) or 7 days (regression study) after CNV induction. After 14 days, the mice were perfused with fluorescein-labeled dextran, and the CNV area was measured on choroidal flatmounts.

Results:: In the inhibition study, either pegaptanib, VEGF Trap_R1 or VEGF Trap_R2 significantly suppressed CNV formation as compared to the vehicle group (p<0.05). In the regression study either VEGF Trap_R1 or VEGF Trap_R2 significantly reduced CNV size (p<0.05). In contrast, treatment with pegaptanib did not result in a significant reduction of CNV size when given 7 days after CNV induction.

Conclusions:: Treatment of experimental CNV with either pegaptanib or VEGF Trap can effectively suppress the formation and the early development of experimental CNV, whilst VEGF Trap, seems to work more efficiently than pegabtanib on established CNV.

Keywords: choroid: neovascularization • growth factors/growth factor receptors • drug toxicity/drug effects